Suspension for balance plates



J'. T. F. CONTI.

SUSPENSION FOR BALANCE PLATES.

APPLICATION FILED IuIII: 5. Iszo.

1,424,239. v n P..IenIedAug 1,1922x 2 SHEETS-SHEET l.

J. T. F. CONTI.

SUSP ENS!0N FOR BALANCE PLATES. APPLICATION HLED JUNE 5, 1920.

1 ,424,23 9. Patented Aug. 1, 1922.

2 SHEETS-SHEET 2.

JMES TBURCE Feux Conn per #im `UNI-'USD i STATES PATENT oFF1cE.-

JAMES Trennen FELIX coN'r1,`-or rams, FRANCE, Assrenon rosocrnfrn INDUS- TRIELLE DINSTRUMnNrs DE rnncis'ron, or* rams, FRANCE'.

' SUSPENSION FOR- BALANCE PLATES.

Specification or" Letters llatent. 1:fLtQ11ted`Aug. 1, 1922.

Application filed June `5, 1920. Serial No.,386,7172.

To al "whom, it may conce/rn;

Be it known that I, JAMES TIBURGE FELIX Uormi, of Paris, France, a citizen ot the Frenchflepublic, have invented Suspensions for Balance `Plates, of which the following is a. t'ull, clear, and exact description.

It is known that balancesy which are provided with platform plates, that is to say not suspended by wires or chains, necessitate a multiplicity ot knife-edges and ot four-bar motions combined in such a manner as to obtain a constant indication of weight, whatever may bey the point of the plate 'where bears the load. s i

This invention relates to an extremely simplel arrangement which may be advantageously' `applied on any balances in which the amplitudeof vertical oscillation of the plate is very reduced. This arrangement, by suitably limiting the strokes ot' the suspension knife-edges, may be applied to any balances, but it is more particularly convenient for Conti and Roman balances in which a vertical displacement nearly nil can be given to the knifeedge supporting the load.

The invention consists, substantially, in mounting the plate on two vertical members, resting on one another and capable of moving verticallyaceording to a very small extent, but the inclination of which to the vertical is re-ndered impossible by means of flexible and inextensible wires stretched hori Zontally.

By means ot this device, it is possible to do entirely away with the lateral pressures of the suspension knife-edge, whatever may be the point of application ot the load on the late. p Various methods ot carrying out the invention are diagrammatically illustrated, by way of example only, in the accompanying drawing, in which:

Figures l and 2 illustrate in elevation and plan view respectively a Roman balance provided with the suspension device torming the subject-matter of the invention.

Figure 3` shows this device lapplied to a Conti balance and Figures t and 5 illustrate the application of the device to an ordinary balance with two plates.

Referring to the drawing, it will be seen, in the example illustrated in Figs. l and 2,

that the plate a of the Roman balance is integral `with a tube y This tube l) is held vertically by means of two horizontal cross pieces each constituted by four iiexible and inextensible Wires or small chains c arranged crosswise, one ot' these cross pieces being located immediately underneath the plate a and the other at the lower part ot the tube b. lThe ends of each ot' theilexible wiresk c are attached on the one hand tothe tube Z) and on the other hand to stretching devices d. suitably carried by supporting columns d1.

The tension of thevarious flexible ele' ments c forming the two cross pieces is adjusted in such a manner as to allow the plate a, it' it is tree, to have a movement of a few millimeters above and under the horizontal position of the said elements.

A. rigid rod e which is convex at its upper part and concave at its lower part, rests on a knife-edge ,t ot the Roman balance and supports at g the weight of the platea.

The length of this rod is determined in such a manner that, when the indexes [L z' are opposite each other, the inner points of attachment of the flexible wires c are very slightly above the horizontal plane in whic are located the outer attachment members or stretching` devices d of the cross pieces.

The apparatus being in equilibrium in this position. with a mass j, if this mass is placed on one of the sides of the plate a, as indicated in Fig. l, the various wires c constituting the cross pieces are stretched,y

but as they are practically horizontal, there does not exist any component capable of introducing` a modiiication in the pressure supported by the knite-edge f. i

Moreover, as the rod c and the knife-edge f do not support any lateral stress, the stress transmitted by this knife-edge f remains constant whatever may be the position of the mass j on the plate a.

Figure 3 illustrates the method of suspension applied to a Conti balance.

ln this case, the plate a of the balance is integral with a rigid member b1 held laten ally and both ends by cross pieces constituted, `as stated above, by flexible wires c.

This member rests on a vertical rod e which transmits the weight to the suspension knife-edge It' of the balance.

The weighing is effected, in this system,

by means of a steel-yard la having a Weight Ztl, the knife-edge Z of which rests on a support integral with an arm m rocking about an axis substantially coinciding With the peak of the suspension knife-edge f of the balance.

The arm m rests, through a rolling path- Way fm1, on a roller n mounted on a nut moving on a vertical screw p the number of revolutions of which registered on an in dicating dial Q gives the Weight.

In the two examples illustrated, the balances comprise a single plate which transmits the pressure through a vertical rod to the end of this rod.

W'hen7 as in the case illustrated in Figs. JC and 5, the balance comprises tvvo plates, the vertical rod can be replaced by frames b2 with knife-edges.

In case the first l nife-edge thus receiving the load is of great length or composed of two elements Widely spaced apart, the vertical rod may be replaced by a frame b2 supporting a second frame b3 integral With the plate a, as diagrammatically illustrated in F ig. 5.

In this case, the cross pieces comprise only tivo flexible Wires c instead of four, as it suffices for the plate to be held on one direction Only.

The constructional arrangements above described are of course given by way of example only and it is obvious that they can be modified according to the various types of balances Without departing thereby from the principle of the invention.

Claim:

In a balance, a balance plate, a suspension device therefor comprising a substantially vertical member extending rigidly from the plate7 afknie-edge suspension, a second vertical member supporting the first verti cal member and thereby the plate on the knife-edge, and a plurality7 of flexible inextensible filaments stretched horizontally between fixed points of the balance and the first vertical member in such a manner as to permit only very slight vertical movements ol' the balance plate and to eliminate lateral pressure on the knife-edge.

The foregoing specification of my sus pension for balance plates77 signed by me this 14th day of May, 1920.

JAMES TIBURCE FELIX CONTI. 

